Ethyl ester. 



On the whole (1 yields a «^ood coiislaiit value A.s the value of 

 G happens to be larger than J for the I'tlnjl ester, and smaller 

 than I for the inethi/l ester, it was to be foreseen that when the 

 two isoineis of the ethyl ester at (j() are left in contact with the 

 satnrate solution, the neutral form vanishes entirely, whereas the 

 reverse must take place with the methyl ester. Experiment was in 

 perfect harmony with tiiis, so that the investigation of tiiese isomers 

 yielded a fine (|nalitative confirmation. 



3. A relation of general validiti/, Inj means of inlncti both for 

 isomers and for polymers it can be decided in an e,iveediiir/h/ simple 

 way mhich modification is the stable one. 



Tlie substances discussed hei'e present the phenomenon of mole- 

 cular allotropy, because they are built up of two kinds of molecules. 

 Besides they present the phenomenon of phase allotropy, because 

 the substance appears in two solid phases. 



Hence the snl)stance without solvent belongs to tiie pseudo binary 

 systems, and only when the dill'erent kinds of molecules in the 



